1. Field of the Invention
The present invention relates generally to a computer implemented method, a data processing system, and a computer program product. More specifically, the present invention relates to a computer implemented method, a data processing system, and a computer program product for the smart scheduling of automatic partition migration by the user of timers.
2. Description of the Related Art
Increasingly large symmetric multi-processor data processing systems are not being used as single large data processing systems. Instead, these types of data processing systems are being partitioned and used as smaller systems. These systems are also referred to as logical partitioned (LPAR) data processing systems. A logical partitioned functionality within a data processing system allows multiple copies of a single operating system or multiple heterogeneous operating systems to be simultaneously run on a single data processing system platform. A partition, within which an operating system image runs, is assigned a non-overlapping subset of the platforms resources. These platform allocable resources include one or more architecturally distinct processors and their interrupt management area, regions of system memory, and input/output (I/O) adapter bus slots. The partition's resources are represented by the platform's firmware to the operating system image.
Each distinct operating system or image of an operating system running within a platform is protected from each other, such that software errors on one logical partition cannot affect the correct operation of any of the other partitions. This protection is provided by allocating a disjointed set of platform resources to be directly managed by each operating system image and by providing mechanisms for ensuring that the various images cannot control any resources that have not been allocated to that image. Furthermore, software errors in the control of an operating system's allocated resources are prevented from affecting the resources of any other image. Thus, each image of the operating system or each different operating system directly controls a distinct set of allocable resources within the platform.
With respect to hardware resources in a logical partitioned data processing system, these resources are shared disjointly among various partitions. These resources may include, for example, input/output (I/O) adapters, memory DIMMs, non-volatile random access memory (NVRAM), and hard disk drives. Each partition within a logical partitioned data processing system may be booted and shut down over and over without having to power-cycle the entire data processing system.
During operation, it is often necessary to migrate the operating system from a partition on a first logical partitioned data processing system to a partition on a second logical partitioned data processing system. Partition migration can be an intensive and disruptive task to the operating system executing within the migrated partition. Partition migration often involves shutting down or quiescing applications in order to accurately move data and state information from the sending partition to the receiving partition. After migration, the current state and system configuration must then be restored. Partition migration will therefore generally necessitate some inconvenience to an operator during the time required for partition migration.